My invention is an improvement over the puzzles shown in my prior patents, U.S. Pat. No. 3,608,906 dated Sept. 28, 1971, U.S. Pat. No. 3,687,455 and my French Pat. No. 1,582,023. These puzzles, as well as other related types of puzzles having domino-like rules of assembly typically are characterized by regular polyhedral shaped pieces which result in the puzzle having either many pieces and being very complex or relatively few pieces and being very easy to solve. It is among the objects of the invention to provide a puzzle of the general type described which has a moderate number of pieces and which is of medium complexity.